Currently, the FDA awards only three years of exclusivity if a fixed-dose combination drug contains a previously approved ingredient, and if a drugmaker conducted new clinical studies that were essential to approval.

FORBES: Gilead Challenges FDA Over Exclusivity For Its Latest AIDS Drug

Then, they seek FDA approval of a fixed-dose combination including that drug.

FORBES: Gilead Challenges FDA Over Exclusivity For Its Latest AIDS Drug

The pill, a fixed combination of two generic ingredients, is the first drug tested only in African-Americans.

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